Flaw detector mechanism



Sept. 1'1, 1934. H, C, BRAKE 1,973,528

FLAW DETECTOR MECHAN ISM Filed Nov. l, 1933 l torneg Patented' sept. 11, 1934 A e 1,973,528

UNITED STATES PATENT oFFlcE mw DETECTOR MEonAmsM Harcourt C. Drake, Hempstead, N. Y., assignor .to Sperry Products, Inc., Brooklyn, N. Y., a

corporation of New York Application November 1, 1933, Serial No. 696,178

s claims. o1.1'75`1s3) This invention relates to naw detector mechadetector car within which is located a generator nisms forl electrical conductors, and more par- G designed to supply current to sets Yof brushes ticularly to the type of mechanism employed in 11 and 12 supported by a current brush carriage the Sperry rail naw detector cars. The principle 15 which is designed to' ride upon the rail R by of operation employed in said mechanism is now means such as anged wheels 16. The current well known and consists in sending current brush carriage is adapted to be held normally in through the conductor under test to establish an raised or ineffective position by means such as electromagnetic field surrounding the saine and cables 17 and retractile springs (not shown) and then exploring said field with induction means may be lowered to effective position into engageto detect any irregularities in flux set up by the ment with the rail by means such as iluid preso5 presence of flaws within the conductor. Said sure supplied to cylinders 18 to depress pistonirregularities may be caused to induce an E. M. F. rods 19 connected to the current-brush carriage. which, after being suitably amplified, may be When the uid pressure supply is cut off the recaused to operate indicating means such as pens tractilesprings and the cables I1'7 will raise the l5 operating on a, moving chart. current brush carriage. 7o

Since a rail flaw 'detector mechanism con- The current supplied to the railaby sets of structed as above would pick up every rail joint brushes 11, 12 will establish an electromagnetic in the same manner as a aw, due to the fact field surrounding the rail and said field will be that 'at each rail joint there are angle bars, bolts. uniform except in the region of aw. Irregu- 20 ete. Which diStOrt the electromagnetic eld, means larities in the electromagnetic eld surrounding are Provided in the Sperry ear fOr Cutting Out the rail are designed to be detected by inductive the indicating means when the detector mechameans such as a pair of coils 20 housed in housnism is passing over a rail joint. ing 21 supported on a detector carriage 22 adapt- In Certain tyDeS 0f railroad Construction, pared to ride upon the rails on means such as wheels 25 ticularly that used on certain European railways, 23, said detector carriage being in turn supportthere iS provided in addition t0 the rail J'Ont angle ed on the current brush carriage for movement bars, intermediate angle-bars or clamps which independent thereof by means of a. limited unigrip the rail and fasten it to the ties at a point Aversa! connection comprising loose-fitting bolts between the rail joints. Such intermediate 24 and springs 25. Variations in the current supclamping means would ordinarily also actuate the ply will have no eiiect upon the induction coils joint-cutout mechanism to cut out the indicat- 20 because the coils are of equal inductance and 85 ing means while the detecting means was pass: voppositely connected. The coils normally cut a ing Over the intermediate Clamp- HOWever, it iS constant number of lines of force; but on enternot desirable to cut out the indicating mechanism ing e, region of flaw, one of said coils will cut a at this point because it results in failure-oi the different number of lines of force to generate 90 detecter mechanism t0 test Certain Parts 0f the a differential E. M. F. which, after being suitably rail. Therefore, the principal object of my-.inamplified by amplifier A, may be caused to Opervention is the'provision of means which would ate any suitable indicator such as pens P and prevent actuation of the indicator cutout mecha P' operating on a moving chart.

40 niSm by means Other than the rail J'OintS- The output of amplifier A operates pens P and 95 Further Objects andadvantages of this inven- P' by means such as relays 30, 31 which are of tion will become apparent in the following dediii'erent strengths so that a weak flaw will cause tailed description. only relay 30 to attract its armature 30' and In the accompanying drawing, A I close contacts 32 through pen relay 34, while a Fig. 1 is a side elevation of a portion of a Sperry strong output of amplier A due to a substantial 160 rail naw detector car to-which my invention is region of flaw will cause both output relays 30 adapted to be applied. and 31 to attract their armatures 30' and 31 Fig.l 2 iS a Wiring diagram illustrating the printo close contacts` 32 and 33 and actuate two pen ciple. of my invention. relays 34 and 35 to actuate pens P and P'. Said Fig. 3 is a plan view of a French type rail road pens normally trace a straight linelon a moving 105 construction showing an intermediate Clamping chart but when actuated bythe relays 34 and member which would ordinarily operate the ind'i- 35 they will make a jog in the line to indicate thecator cutout means. presence o1' a flaw.

Referring to Fig. 1 of the drawing,Ihave shown It will be seen that when passing over a rail a portion of the car body 10 of a Sperry rail naw joint, the detector mechanism would pick up un said rail joint and the result would be that pens P and P' would give a series of indications at each rail joint. This is undesirable since it tends to complicate the record and makes it diilicult to detect an indication of flaw close to the rail joint. For this reason, means are provided for cutting out the operation of pens P and P' when the detector mechanism is passing over a rail joint. Said means comprises fingers 40 and 41 in advance and to the rear of the detector mechanism 20, said fingers being designed to engage the side of the rail so that they will contact with the angle-bars 42 at the rail joint. Said i'lngers are pivoted, as shown in Fig. 2, so that Aupon engagement with the angle-bar at a rail joint they Will close contacts 43, 44 which will close a circuit extending through a joint cutout relay 45 which will attract its armature 46 to break contacts 47, 48' which are in the line 'between contacts 32, 33 and the pen magnets 34, 35. At the same time that armature 46 is attracted to break contacts 47, 48, contacts 48, 49 will be made to energize a joint pen magnet 50 to operate a joint pen J which will indicate on the chart that a joint has been encountered. 'The joint cutout fingers 40, 41 are so positioned that finger 41 engages the angle-bar 42 before finger 40 has left it, so that throughout the entire passage. of the detector mechanism over the rail joint the pens P and P will be ineffective. As soon as the finger 41 has left the angle-bar the pens are again ready to operate.

In certain types of railroad construction, such as is found in France, there are clamp plates 60 for fastening the rail to a tie at an intermediate point in the length of the rail. It will now be seen that when fingers 40 and 41 engage said clamp plate 60 they willcut out the indications of pens P and P two successive times, rst, when finger 40 engages said clamp plate, and later when nger 41 engages said clamp plate. Since the clamp plate 60 is of lesser length than clamp plate 42, there will be an interval between the times that finger 40 and finger 41 render the pens P and P ineffective. Thus, there will be two parts in the intermediate section of the rail which will' not be tested, i. e. the parts over which the detector mechanism passes while fingers 46 and`4l engage clamp-plate 60. Or, stated another way, although the detector mechanism passes thereover and responds to any flaws therein, such flaws will have no effectupon the pens P and P' which are temporarily rendered inef- -fective by the two successive operations of nfollowing means which has for its object to prey vent the joint cutout mechanism from rendering the pens P and P' ineffective for a predetermined interval after a rail joint has been passed over, said interval being suflicient to allow the car to pass beyond the intermediate clamp plate. This construction takes the form of a pair of contacts 70, 71 in the circuit of magnet 45 which is designed to break contacts 47, 48 to render the-pens ineffective. One of said contacts 7l is part of an armature 72 designed to be attracted by delayed-action magnet 73 in parallel with the magnet 45. .Contacts 70 and 71 are. normally closed so that the circuit through magnet 45 will be completed by the closing of contacts .43, or 44. Another set of contacts 75, '76, normally open, are connected in parallel with contacts 70 and '71 to form a by-pass around the same. One of the contacts 75 may be part of an armature 77 designed to be attracted by the rapid-acting magnet 78, likewise in parallel with magnet 45.

By theconstruction described above, the operation when cutout finger 40 engages the angle-bar is as follows: Contacts 43 are closed and the cir` cuit through magnets 73, 78 and 45 is closed by reason of the closed contacts 70, 71 which are delayed slightly in opening because magnet 73 is a delayed-action relay. By the time contacts 70, 71 have opened, contacts 75 and 76 have closed because relay 78 is a rapid-acting relay. Thereafter, it does not matter if contacts 70, 71 are open, the magnets 73, 78, and 45 will remain energized by reason of the fact that the circuit is now completed by way of the by-pass ,through contacts 75, 76. Magnet 45 attracts its armature 46 to break contacts 47 and 48 and render the pens P and P ineffective until joint finger 41 has passed beyond the angle-bar.

When said joint finger 41 has passed beyond the angle-bar, the circuit through magnets 73, 78 and 45 is broken and the armature 46 returns to its original position to close contacts 47, 48 and render the pens P and P again effective. Contacts 75 and 76 also open. Contacts 70 andr 71 do not close, however, for a predetermined interval of time, by reason of the fact that armature 72 is connected to a delayed-action mechanism such as a one-way dash-pot 80 which will delay the closing movement of contact 71 toward contact 70 for an interval of time which is determined by the rate of travel of the car over the rails and the distance betweenvangle-bar 42 and clamp plate 60. Said'dash-pot is adjusted so that contacts 70 and 7l will close when the car has passed substantially beyond clamp plate 60. Thus, it will be seen that even though fingers 40 and 41 engage the clamp plate to close contacts 43 and 44, magnet 45 is not energized to attract armature 46 because the circuit through magnet 45 is open at points 70 and 71.

Not only will the above described mechanism prevent rendering the pens P and P ineffective by a central clamp plate, but it will also prevent operation of the joint fingers 40 and 4l by means of overhanging pieces of rail which have become detached from the main railhead. In fact, the period of time which elapses before contacts 70 and 71 close may be so adjusted that once contact finger 40 has closed contacts 43, contacts 70 and '7l will not close again until substantially a rail length has been covered, that is, until contact finger 40 is within striking distance of the next angle-bar 42. Thus, any factors along the railhead which would tend'to operate the joint cutout fingers will not be effective to cut out pens P and P', but only the angle bars 42 at the rail joints will have such effect.

In accordance with the provisions of the patj ent statutes, I have herein described the principle and operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire .to have it understood that the apparatus shown is only illustrative and that the invention can'be carried out by other means. Also, while it is designed to use the various features and elements in the combination and relations described, some of these may be altered and others omitted without interferring with thel more general results outlined, and the invention extends to such use'.

Having described my invention, what I'claim and desire to secure by Letters Patent is;

1. In a flaw detector car adapted to travel) along the rails, the adjacent rails being joined together, means responsive to iiaws, indicating means, means whereby said responsive means actuates said indicating means, means adapted to cooperate with the rail joint for rendering said actuating means ineiective when said responsive means passes over a rail joint, and means for preventing said cooperating means from 'again renderingsaid actuating means ineiTective for a predetermined interval after said cooperating means has passed out of cooperative relation with the rail joint.

'2. In a iiaw detector car adapted to travel along the rails, the adjacent rails being joined together, means responsive to aws, indicating means, means whereby said responsive means actuates said indicating means, joint cut-out members adapted to engage the rail joint for rendering said actuating means ineffective when said responsive means passes over the rail joint, and means for preventing said members from again rendering said actuating means ineffective for a predetermined interval after said members have passed beyond the rail joint.

3. In a iiaw detector car adapted to travel along the rails, the adjacent rail's being joined together, means responsive to i'iaws, indicating means, means whereby said responsive means actuates said indicating means, means adapted `to cooperate with the rail joint for rendering said actuating means ineffective when said responsive means passes over a rail joint, and means for preventing said cooperating means from again rendering said actuating means ineiective for a predetermined interval after said cooperating means has passed out of cooperative relation with the rail joint, said last-named meansy including an operating mechanism adapted to be operated out of normal position when said cooperating means is in cooperative relation with the rail joint, and delayed action means for restoring said mechanism to normal.

4. In a flaw detector car adapted to travel along the rails, the adjacent railsbeing joined together, means responsive to flaws, indicating means, means whereby said responsive means actuates said indicating means, means adapted to cooperate with the rail joint for rendering said actuating means ineffective when said responsive means passes over a rail joint, and means for preventing said cooperating means from again rendering said actuating means ineffective for a predetermined interval after said cooperating means has passed out of cooperative relation with the rail joint, said last-named means including an electric connection, means whereby said cooperating means when in cooperative relation with said rail joint breaks said connection, and delayed action means for re-establishing said connection.

5. In a flaw detector car adapted to travel along the rails, the adjacent rails being joined together, means responsive to iaws, indicating means, means whereby said responsive means actuates said indicating means, means adapted to cooperate with the rail joint for rendering said actuating means ineiective when said Aresponsive means passes over a rail joint, and means for preventing said cooperating means from again rendering said actuating means ineffective for a predetermined interval after said cooperating means has passed out of cooperative relation with the rail joint, said last-named means including an electric circuit, a circuit-controlling `device in said circuit for normally closing the same, means a whereby said cooperating means when in cooperative relation with said rail joint actuates said device to open the circuit, and delayed` action means for delaying the return of said device to normal position.

6. In a flaw detector car adapted to travel along the rails, the adjacent rails being joined together, means responsive to flaws, indicating means, means whereby said responsive means actuates said indicating means, means adapted to cooperate with the rail joint for rendering said actuating means ineiective when said responsive means passes over a rail joint, and means for preventing said cooperating means from again rendering said actuating means ineffective for a predetermined interval after said cooperating means has passed out of cooperative relation with the rail joint, said last-named means including an electric circuit normally eiective to be energized by said cooperating means when in cooperative relation with the rail joint, means whereby said cooperating means energizes said circuit when in cooperative relation with the rail joint, means actuated by said cooperating means when in cooperative relation with the rail joint for rendering said circuit ineiective when said cooperating means has passed out of cooperative relation with the rail joint, and delayed action means for rendering said circuit effective.

7. In a aw detector car adapted to travel along the rails, the adjacent rails being joined together, means responsive to iiaws, indicating means, means whereby said responsive means actuates said indicating means, joint cut-out members adapted to engage the rail joint for rendering said actuating means ineffective when said responsive means passes over the rail joint, and 115 means for preventing said members from again rendering said actuating means ineffective for a predetermined interval after said members have passed beyond the rail joint, said last-named means including an electric connection, means 120 whereby said connection is broken when said members engage the rail joint, and delayed 'action means for re-establishing said connection.

8. In a ilaw detector car adapted to travel along the rails, the adjacent rails being joined 125 together, means responsive to ilaws,.indicating means, means whereby said responsive means actuates said indicating means, joint cut-out members adapted to engage the rail joint for rendering said actuating means ineflective when 130 said responsive means passes over the rail joint, and means for preventing said members from again rendering said actuating means ineffective for a predetermined interval after said members have passed beyond the rail joint, said last-named 135 means including an electric circuit normally effective to be energized when said members engage the rail joint, means whereby said circuit is energized when said members engage the rail joint, means actuated by said members when in engagement with the rail joint, for rendering said circuit ineffective when said members have passed beyond the rail joint, and delayed action means for rendering said circuit eilective.

HARCOURT C. DRAKE. 

